java 矩阵乘法的mapreduce程序实现

2024-02-20 16:12:07 65

packagecom.cb.matrix; importstaticorg.mockito.Matchers.intThat; importjava.io.IOException; importorg.apache.hadoop.conf.Configuration; importorg.apache.hadoop.io.Text; importorg.apache.hadoop.mapred.FileSplit; importorg.apache.hadoop.mapreduce.Mapper; importcom.sun.org.apache.bcel.internal.generic.NEW; publicclassMatrixMapperextendsMapper{ privateTextmap_key=newText(); privateTextmap_value=newText(); privateintcolumnN; privateintrowM; /** *执行map()函数前先由conf.get()得到main函数中提供的必要变量 *也就是从输入文件名中得到的矩阵维度信息 */ @Override protectedvoidsetup(Mapper.Contextcontext)throwsIOException,InterruptedException{ //TODOAuto-generatedmethodstub Configurationconfig=context.getConfiguration(); columnN=Integer.parseInt(config.get("columnN")); rowM=Integer.parseInt(config.get("rowM")); } @Override protectedvoidmap(Objectkey,Textvalue,Mapper.Contextcontext) throwsIOException,InterruptedException{ //TODOAuto-generatedmethodstub //得到文件名，从而区分输入矩阵M和N FileSplitfileSplit=(FileSplit)context.getInputSplit(); StringfileName=fileSplit.getPath().getName(); if(fileName.contains("M")){ String[]tuple=value.toString().split(","); inti=Integer.parseInt(tuple[0]); String[]tuples=tuple[1].split("\t"); intj=Integer.parseInt(tuples[0]); intMij=Integer.parseInt(tuples[1]); for(intk=1;k

reduce函数：对于每个键（i,k）相关联的值（M,j,m(ij)）及（N,j,n(jk)）,根据相同的j值将m(ij)和n(jk)分别存入不同的数组中，然后将俩者的第j个元素抽取出来分别相乘，最后相加，即可得到p(jk)的值。

reducer

packagecom.cb.matrix;


importjava.io.IOException;

importorg.apache.hadoop.conf.Configuration;
importorg.apache.hadoop.io.Text;
importorg.apache.hadoop.mapreduce.Reducer;



publicclassMatrixReducerextendsReducer{
privateintsum=0;
privateintcolumnM;
@Override
protectedvoidsetup(Reducer.Contextcontext)throwsIOException,InterruptedException{
//TODOAuto-generatedmethodstub
Configurationconf=context.getConfiguration();
columnM=Integer.parseInt(conf.get("columnM"));
}
@Override
protectedvoidreduce(Textarg0,Iterablearg1,Reducer.Contextarg2)
throwsIOException,InterruptedException{
//TODOAuto-generatedmethodstub
int[]M=newint[columnM+1];
int[]N=newint[columnM+1];

for(Textval:arg1){
String[]tuple=val.toString().split(",");
if(tuple[0].equals("M")){
M[Integer.parseInt(tuple[1])]=Integer.parseInt(tuple[2]);

}else{
N[Integer.parseInt(tuple[1])]=Integer.parseInt(tuple[2]);
}
for(intj=1;j
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java 矩阵乘法的mapreduce程序实现

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